Ski binding for a cross-country or touring ski

ABSTRACT

A ski binding for attachment to a ski and for retaining a ski boot having a hook element extending therefrom, comprises a support structure for disposition on the upper surface of a ski, a horizontal transverse pin attached to the support structure, a pivoting part having a first end, a second end, and a mid-portion disposed between the first and second ends, the first end including a pivot pin disposed thereon, the second end having at least one locking pin extending therefrom, and the mid-portion being pivotably connected to the horizontal transverse pin, an elastic element disposed on the support structure for contacting the pivoting part to resist pivotal movement of the pivoting part about the transverse pin, a boot retaining shell pivotably mounted about the transverse pin for movement between an opened position and a closed position and having a recess disposed therein, the locking pin for projecting through both the recess and the hook element of a ski boot when the retaining shell is in the closed position, and for releasing the hook element of the ski boot when the retaining shell is in the opened position, a spring biasingly disposed between the pivoting part and the retaining shell for urging the retaining shell to the opened position, and a spring plunger pivotably mounted about the pivot pin of the pivoting part for locking the retaining shell in the closed position.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a ski binding for a cross-country or touringski.

2. Description of the Related Art

The type of ski binding mentioned in the introduction is described inAustrian Patent B 357,081. This binding is put on by inserting the soleextension of the ski boot into a retaining shell, during which procedureconverging side walls of the stirrup facilitate the insertion. When theretaining shell is then pressed down, which causes the binding to belocked, locking pins enter retaining shell and openings in the soleextension of the ski boot. One disadvantage of this binding is that theretaining shell with its sole plate tilts about an axis located ratherfar behind and that the swivel axis for the relative motion of theretaining shell and the pivoting part carrying the locking pins liessubstantially above the ski surface, thus preventing a natural rollingmovement of the sole of the foot on the upper side of the ski. Theinsertion of the ski boot into the retaining shell from the bottomupwards is unnatural and thus uncomfortable. Furthermore, the anchoringof the retaining shell on the lateral surfaces of the ski isdisadvantageous for reasons of stability. Also, arrangement of a movableelement projecting outwards from the lateral surfaces of the skideleteriously affects the skier's motions.

The invention has for its object to adapt, in a ski binding of the kindreferred to in the introduction, the skier's stepping into the bindingwith the ski boot and his striding to the natural motions of the footand to provide a compact arrangement of the entire ski binding.

This object is achieved by the features of the present invention.

The expedients advocated by the invention ensure an easy and safestepping into the binding and natural motions during the striding. Thewhole binding has a compact construction so that there are no componentsthat would protrude from the sides of the ski.

With the ski binding which is described in an older non-prepublishedEuropean Application (No. 85112147.5) of the applicant and whichconstitutes an internal state of the art, retaining shell and pivotingpart can be pivoted about a common transverse pin against an elasticelement. This transverse pin is held by a supporting structure mountedon the ski. The transverse pin is located in the front area of the twoaforementioned components and a spring exerts pressure on retainingshell and pivoting part with the object of forcing them apart.Furthermore, the spring plunger is mounted on an extension of thepivoting part on a pin and, when the binding is in the closed position,locks into a crossbar--provided with a latching groove--of the retainingshell.

Generally, this construction has stood the test of time, but theretention of the ski boot was unsatisfactory, because it wobbled in theretaining shell. In addition, the presence of snow in the binding madestepping-in difficult. Also, there was no expedient that would preventthe spring plunger from opening inadvertently when it strikes anobstacle during striding. The spring that serves to force apartretaining shell and pivoting part is limited in its dimensions, and thusalso in its action, because of design considerations. On stepping intothe binding, the retaining shell could swing downwards even before theski boot was firmly seated in the retaining shell because of its limitedclosing force.

To overcome the disadvantages of this older approach, the invention aimsat achieving several objects, which will be discussed hereinbelow. Afirst object is to improve the retention of the ski boot in theretaining shell, even in the event that there is snow in the binding.

This object is achieved by the present invention.

The expedients taught by the invention ensure good retention of the skiboot in the retaining shell.

By virtue of the expedients of the present invention the optimum angleof the bearing surfaces is fixed at about 45° so that, on the one hand,if snow is deposited on the bearing surfaces the longitudinaldisplacement of the ski boot does not become excessive, which would bethe case if the angles were smaller and would thus lead to a heavy loadon the locking pin or on the hook-up element and, on the other hand, thebearing surfaces would still offer the ski boot sufficient lateralsupport, which would no longer be the case if the angles were greater.The binding will be less sensitive to limit testings because of theseexpedients.

A combination of the features of the present invention will result in avery advantageous construction of the front area of the ski boot.

The features of the present invention permit a snug fit of the hook-upelement to the locking pin.

The present invention also produces other advantageous constructions ofthe hook-up element.

In addition, the features of the present invention define the supportingsurfaces on the ski boot, with which the latter is propped up againstthe bearing surfaces of the retaining shell. These features also definethe guide surfaces of the ski boot, such that the lower guide surface ofthe ski boot rests on the bottom of the retaining shell and the upperguide surface abuts from below on the guide ledges of the retainingshell.

The present invention also provides a plurality of openings in theretaining shell which ensure that snow in the binding will be expelledupon stepping into the binding. Combining the features of the inventionresult in guiding the snow in the binding to the openings in theretaining shell.

The present invention results in a design of the surface of the lockingpin along which slides the hook-up element upon stepping into thebinding until it reaches its final position. The spacings betweensupporting surfaces and hook-up element are chosen such that the hook-upelement is under tensile stress after the ski boot has been insertedinto the binding.

According to a second object of the invention, the spring plunger is tobe provided with an additional catch without increasing the number ofcomponents.

According to the invention, the spring plunger has an additional catch,ruling out inadvertent unlocking during striding due to stresses andshocks.

The third object is to ensure that stepping into the binding alwaysoccurs under controlled conditions.

As a result of the expedients taught by the invention, the closing forceof the retaining shell is increased upon stepping into the bindingwithout additional parts and without reinforcing the springs that serveto ensure that stepping into the binding always occurs under controlledconditions.

The present invention ensures that the angle of traverse of the springplunger during the closing of the binding is equal to the minimum angleof traverse during the opening thereof.

By virtue of the construction of the invention, the position of thespring plunger and of the retaining shell relative to each other in theopen position of the binding is fixed.

In all the versions described above, the spring plunger, during theentire stepping-out procedure, must be held in the position in which hereleases the pivoting part.

Accordingly, the invention has as fourth object the overcoming of thisdrawback as well and the provision of a ski binding in which the userhas the possibility of supporting himself on the cross-country trackwith both ski poles during the stepping-out procedure.

A ski binding for cross-country skiing as taught by West German PatentA1 34 05 861 features a base plate which extends towards the tip of theski in two cheeks, between which is a placed a grip lever which is underthe influence of a torsion spring. The torsion spring presses the griplever against a hold-down clamp for the ski boot sole and which can bepivoted about a further transverse pin placed between the cheeks and onwhich a step spur is also mounted. The step spur locks with its end frombelow into a recess of the sole of the ski boot.

In the stepping-in position of the binding, the hold-down clamp is heldin place by the grip lever in that a guide curve of the grip lever lapsover a cam of the hold-down clamp. When the sole of the ski bootapproaches the base plate during the stepping-in procedure, the cammigrates along the guide curve and when the culmination point isexceeded, the hold-down clamp is swung into the locking position.

This binding has the drawback that the stepping motion of the skier isproduced only by the elasticity of the sole of the ski boot but not by ajoint plate in the binding. Therefore, this prior type of solutiondiffers from the subject matter of the invention.

Obviously, various approaches are possible for the practicalconstruction of the spring plunger, but the design defined in theinvention has proved particularly suitable. With this design, only oneadditional torsion spring is needed to produce the desired effect.

In principle, it would be possible, in order to retain the leg of thetorsion spring projecting into the groove of the spring plunger andwhich is relatively small in size, to provide a flat part in the bottomof the arcuate groove, on which the end of the spring is fixed byfriction. However, this could occasionally lead to an unintentionalswing of the spring plunger. This is prevented by the present invention.

The present invention overcomes the danger that the tip of the torsionspring leg does not get stuck in the spring plunger.

The present invention enables the spring plunger to return automaticallyto its indexed position as soon as the end of the leg has been pressedby the crossbar of the retaining shell over the latching projection ofthe groove.

The present invention increases the operational safety of the skibinding, since the necessary spring force is split into two halves of astirrup, thereby considerably reducing the danger of buckling of theloaded leg of the torsion spring.

Further features, advantages and details of the invention will now bedescribed in more detail in conjunction with the accompanying drawingsin which two specific embodiments of retaining shell and ski boot, aswell as two embodiments of the spring plunger, have been set forth forpurposes of illustration.

SUMMARY OF THE INVENTION

A ski binding for attachment to a ski and for retaining a ski boothaving a hook element extending therefrom, comprises a support structurefor disposition on the upper surface of a ski, a horizontal transversepin attached to the support structure and extending transverse to theupper structure of the ski, a pivoting part having a first end, a secondend, and a mid-portion disposed between the first and second ends, thefirst end including a pivot pin disposed thereon, the second end havingat least one locking pin extending therefrom, and the mid-portion beingpivotably connected to the horizontal transverse pin, an elastic elementdisposed on the support structure for contacting the pivoting part toresist pivotal movement of the pivoting part about the transverse pin, aboot retaining shell pivotably mounted about the transverse pin formovement between an opened position and a closed position and having arecess disposed therein, the locking pin for projecting through both therecess and the hook element of a ski boot when the retaining shell is inthe closed position, and for releasing the hook element of the ski bootwhen the retaining shell is in the opened position, a spring biasinglydisposed between the pivoting part and the retaining shell for urgingthe retaining shell to the opened position, and a spring plungerpivotably mounted about the pivot pin of the pivoting part for lockingthe retaining shell in the closed position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts the ski binding incorporating the present invention inthe open, (stepping-in) position;

FIG. 2 the ski binding in skiing position taken along the line I--I inFIG. 5;

FIG. 3 depicts the ski binding of FIG. 1 in the closed position, but notloaded by the ski boot;

FIG. 3a is a detailed view of a portion of FIG. 3;

FIG. 4 depicts the ski binding of FIG. 1 in the "go" position;

FIG. 5 a plan view of the ski binding of FIG. 1 in the skiing position;

FIG. 6 a plan view of a first embodiment of the retaining shell of theski binding with the ski boot inserted therein;

FIG. 7 a side view of a first embodiment of the ski boot for use inconjunction with the present invention;

FIG. 8 depicts a plan view of a second embodiment of the retaining shellof the ski binding after the ski boot has been inserted;

FIG. 9 depicts a side view of a second embodiment of the ski boot;

FIG. 10 depicts a ski binding in accordance with the invention similarto FIG. 1;

FIG. 11 depicts maximum swing of the spring plunger during the closingof the retaining shell;

FIG. 12 depicts a ski binding in accordance with the present inventionsimilar to FIG. 2;

FIG. 13 the ski binding in the skiing position and having a modifiedspring plunger;

FIG. 14 depicts a sectional view taken along the line XIV--XIV in FIG.13;

FIG. 15 depicts the ski binding of FIG. 13 with the spring plungerunlocked;

FIG. 16 depicts longitudinal median section of the ski binding duringthe stepping-out procedure;

FIGS. 17-20 are detailed view of portions of FIGS. 14-16;

FIG. 21 depicts a schematic view of a modification of the spring plungerin accordance with the present invention;

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The first embodiment depicted in FIGS. 1 to 7 and 10 to 12 represents aski binding for a cross-country or touring ski 1 and a ski boot 100associated therewith. On the upper side of a ski 1 is mounted asupporting structure 10 by means of springs 2. It is made up of a baseplate 11 with two walls 12 which start out on the end portion of thebase plate 11 and lead approximately to the center of the base plate 11and carry a transverse pin in the latter area. The plate 11 carries onits front end a rib 13 and on its rear end a bearing surface 13 in whichthe screws 2 are countersunk.

On the transverse pin 20 is mounted a pivoting part 30, which rests withits bottom 31 on the bearing surface 14 of the supporting structure 10.The bottom 31 has, on its side facing away from the ski 1, surfaces 31athat drop off obliquely outwards from the longitudinal axis of thebinding. On the end remote from the transverse pin 20 the bottom 31carries a locking pin of locking beam 32. There is also mounted on thetransverse pin 20 a retaining shell 40, the bottom face 41 of which hasa release 41b for the locking pin 32 and further openings 41a (FIG. 6).Guide ledges 45 are attached at the top to the side walls 42 of theretaining shell 40, which, in their front portion, are connected to acrossbar 43 provided with a latching groove 43a and have bearingsurfaces 44 in their rear area remote from the transverse pin 20.

An extension 33 of the pivoting part 30 projecting upwards from thetransverse pin 20 carries at its upper end a pin 50, to which is hingeda spring plunger 60, which is formed as a two-arm lever and carries onits arm turned toward the retaining shell 40 a fillet-shaped stop 63(FIGS. 10-12), and a detent 61 and, on its second arm turned away fromthe ski 1, depression 62.

In the bottom 31 of the pivoting part 30 are provided appropriatecavities 31b for a spring around the transverse pin 20 to which pressureis applied in order to force the retaining shell 40 and the pivotingpart 30 apart. An interlock spring 80 around the pin 50 biases thespring plunger 60 in the direction of closing to the retaining shell 40.

An elastic element 90 is inserted into the front portion of thesupporting structure 10 such that it rests with its recess 91 above therib 13 of the base plate 11 and is thus supported against the pivotingpart 30 with its portion turned away from the rib 3. The elastic element90 has a hole 92 in order to be able to insert the screw 2 withouthindrance during the mounting of the binding on the ski 1.

The ski boot to be inserted into the binding 100 as shown in FIG. 7 hasin its front area a sole extension 101 made up of extensions 101a and aU-shaped hook-in element 102 integrally cast therein with its legs 102a.An opening 104 is formed between the hook-in element 102 and the endsurface 103 of the sole. Viewed from the side, the front area of thesole has conical guide surfaces 105a, 105b, the lower guide surface 105bbeing intended to be put on the bottom surface 41 of the retaining shell40. The angle between the upper guide surface 105a and the lower guidesurface 105b is identical to the angle between the bottom surface 41 andthe guide ledges 45 of the retaining shell 40, since in the case of theski boot 100 inserted into the binding the upper guide surface 105a isto abut from below on the guide ledges 45 of the retaining shell 40. Thesole area provided with the guide surfaces 105a, 105b featuressupporting surfaces 106 which, after the ski boot 100 has been inserted,abut thereon in parallel to the bearing surfaces 44 of the retainingshell 40.

In a second embodiment illustrated in FIGS. 8 and 9, outwardly flaringopenings 41'a are provided in the side walls 42' of the retaining shell40'. The ski boot 100' associated with this embodiment has bevelledsurfaces 102'c on the external surface of the hook-in element 102'surrounded with sole material.

When stepping into the binding shown in FIG. 1, the ski boot 100 isinserted obliquely upwards with its guide surfaces 105a, 105b into theretaining shell 40 until it abuts with its hook-in element 102 on thedetent 61 of the spring plunger 60, after which it is stepped down, withthe retaining shell 40 being swung downwards against the force of thespring 70 and partly against that of the interlock spring 80. In theprocess, the locking pin 32 enters from below the opening 104 in thesole extension 101 of the ski boot. The bevel of the linear segment 32aof the locking pin 32 serves, in the first phase of the stepping down ofthe retaining shell, to facilitate the threading of the locking pin 3into the opening 104 until the ski boot 100 abuts with its supportingfaces 106 on the bearing surfaces 44 of the retaining shell 40. In thesecond phase, the hook-in element moves further along the linear segment32a, but under increasing tensile stress. In the third phase of thestepping-down process, starting from the transition point 32c from thelinear segment 32a to the circular arc segment 32b, the tensile stressremains constant, as the hook-in element 102 is moving along thecircular arc segment 32b to its final position, since the circular arcsegment 32b has its center in the transverse pin 20. At the same time,the crossbar 43 slides down along the interior of the detent 61 whileapplying pressure thereon in the direction of opening (FIGS. 10-11)until the detent 61 locks into its latching groove 43a, thereby fixingits position. Stepping into the binding occurs against a stepping-inforce, which is higher than the force of the spring 70 designed as asetup spring, in that additional pressure is applied to the interlockspring 80 during the pivoting of the retaining shell 40. This solutionresults merely by constructional steps when designing spring plunger 60and crossbar 43 of the retaining shell 40, thereby enlarging the angleof traverse (α) of the spring plunger (60) upon stepping into thebinding and thereby compressing the interlock spring 80 more heavily.Because the stepping in occurs against the increased spring force,premature, uncontrolled closing of the binding is avoided as long as theski boot 100 is not stuck in the retaining shell 40. In the firstembodiment, snow in the binding is expelled during the stepping-inprocedure through the openings 41a in the bottom surface 41 of theretaining shell 40. In the second embodiment, the snow is passed throughthe bevelled surfaces 102'c on the hook-in element 102' to the openings42'a in the side walls 42' of the retaining shell 40' and expelledtherethrough. Furthermore, snow between pivoting part 30 and retainingshell 40 is passed to the outside through the bevelled surfaces 31a onthe bottom 31 of the pivoting part 30.

After the retaining shell 40 has been completely lowered to the ski 1,when the latter rests on the bearing surface 14 of the base plate 11, asis the case in the skiing position shown in FIG. 2, the hook-in element102 has assumed its lowest position in the circular arc segment 32b ofthe locking pin 32, while the detent 61 of the spring plunger 60 abutson the wall 43b lying in the direction of closing of the spring plunger60. In this position, which is also taken by the user while standing,the spring plunger 60 can be opened by inserting the tip of a ski poleinto its depression 62 and exerting pressure against the force of theinterlock spring 80, during which the ski boot 100, by lifting it,springs out of engagement with the locking pin 32 and can then be pulledout of the retaining shell 40.

FIG. 3 shows the binding in its closed position, but not loaded by theski boot 100. Due to the biasing by the spring 70, the retaining shell40 rises until the detent 61 of the spring plunger 60 lies completely inthe latching groove 43a. In this position, of which in FIG. 3a theengagement of the detent 61 of the spring plunger 60 in the crossbar 43of the retaining shell 40 is shown on a larger scale, the spring plunger60 cannot be opened. In FIG. 3a, the path of the detent 61 during thepivoting of the spring plunger 60 in the direction of opening is plottedin dot-dash lines as a circular arc 200a around the pin 50. However, thespring plunger 60 is prevented from said pivoting by an elevated area43c of the wall of the crossbar 43 lying in the direction of opening ofthe spring plunger 60 and which therefore represents an additionalsafety catch for the spring plunger 60. When a ski boot 100 is insertedinto the binding, it runs through the position shown in FIG. 3 in thefirst phase of the striding. Due to the relative motion of the retainingshell 40 with respect to the pivoting part 30, the hook-in element 102of the ski boot 100 lies in this position in the upper region of thecircular arc segment 32b of the locking pin 32. Upon further raising ofthe ski boot 100 in FIG. 4, one maintains, on the one hand, the indexedposition between spring plunger 60 and crossbar 43 of the retainingshell 40 on the one hand and the position of the hook-in element 102 inthe circular arc segment 32b of the locking pin 32 on the other, so thatretaining shell 40 and pivoting part 30 form one unit and together theyswivel in counterclockwise direction against the force of the elasticelement 90. Snow that accumulates in the binding during the striding isexpelled from the binding through oblique snow-expelling surfaces 15,31c, which are formed both on the base plate 11 and on the underside ofthe pivoting part 30.

One of the essential elements of the invention is the fact that thespring plunger 60 and the crossbar 43 of the retaining shell 40 are soadjusted to each other that the spring plunger 60 assumes an accuratelydefined position both in the open and closed positions. This position isfixed by the position of spring plunger 60 and retaining shell 40relative to each other, which, in the open position of the binding,results from the abutment of an elevated area 43d of the crossbar 43 onthe fillet-shaped stop 63 of the spring plunger 60 and, in the closedposition, by abutment of the detent 61 of the spring plunger 60 on thewall 43b of the latching groove 43a of the crossbar 43 lying in thedirection of closing of the spring plunger 60.

In the specific embodiment shown in FIGS. 10 to 12, the spring plunger60 and the crossbar 43 of the retaining shell 40 are so adjusted to eachother that the position of the spring plunger 60 in the open and closedpositions of the binding are the same. Both during the opening andduring the closing of the binding, the elevated area 43b of the crossbar43 of the retaining shell 40 and the detent 61 of the spring plunger 60slide past each other, during which the retaining shell 40 swings in onedirection and the spring plunger 60 carries out a rocking motion, duringwhich the spring plunger 60 attains a maximum swing, after which itreturns to its initial position. The position of the maximum swivel isfixed by the intersection point 200 of two curves, i.e. by the circulararcs 200a which is described by the elevated area 43d of the crossbar 43around the transverse pin 20. Since in this specific embodiment, theposition of the spring plunger 60 is the same in the closed as well asin the open position and the intersection point 200 has a fixedposition, the angle of traverse 24 (α) of the spring plunger 60 duringthe closing of the binding is identical to the minimum angle of traverse(β) during the opening of the binding. In FIG. 11 the swinging of thespring plunger 60 and of the retaining shell 40 is shown with all theother compo-nents being left out, and only the crossbar 43 of theretaining shell 40 is shown. The position of the spring plunger 60 andretaining shell 40 in the open position of the binding is shown in solidlines. During the closing of the binding, i.e., when the retaining shell50 is being swung down, the crossbar 43 slides down with its elevation43d along the interior of the detent 61, during which it appliespressure to the spring plunger 60 in the direction of opening, until itattains the position of its maximum swing which is shown in FIG. 11 withdotted lines. After this position has been exceeded, the retaining shell40 swings further and the spring plunger 60 abuts with its detent 61 onthe wall 43b of the crossbar 43 lying in the direction of closing of thespring plunger 60, with the spring plunger 60 returning again to itsinitial position. The position of the crossbar 43, when the binding isclosed, is shown with dotted lines in FIG. 11.

Except for the shape of the spring plunger and its spring plunger, theski binding shown in FIGS. 13 to 20 corresponds to the design of whathas been described thus far. Therefore, the other parts of the skibinding are given like reference numerals, even if they differ slightlyfrom the versions shown earlier. The spring plunger and its springplunger are denoted with numbers above 300 for better differentiation.

On the transverse pin 20 there is mounted, in addition to the spring 5as detent for the spring plunger 360, an additional torsion spring 306,which is operatively connected to the spring plunger 360 in a manner tobe described in more detail hereinbelow.

In the lever arm of the spring plunger 360 carrying the detent 361 thereis cut out a groove 364 with a rectangular cross section. At the bottomof the groove 364 is formed, near its end away from the shaft 40, alatching projection 365. The groove 364 extends arch-like between thelatching projection 365 and the end of the groove 364 adjacent to thepin 50.

The above described torsion spring 306, one of the legs 306a of which isanchored in the pivoting part 30, locks with its other leg 306b into thegroove 364. As shown in FIGS. 17 to 20, the end 306c of this leg 306bhas the form of a circular arc, but it may also be provided with aroller. If a normal plane is passed to the axis of the leg at the pointof contact between the end 306c of the leg 306b and the bottom of thegroove 364, the latter will enclose with a tangential plane on thebottom of the groove an angle gamma which is greater than the angle offriction between the materials of the spring plunger 360 and of thetorsion spring 306.

For a better understanding of the effects that can be achieved by amodification of the spring plunger 360, we will first repeat briefly thefunction of the ski binding in accordance with the earlier versions andthen explain the function of the modified version. Here, FIG. 17corresponds to the skiing position of the ski binding, such asillustrated in FIG. 14, and FIG. 18 corresponds to the ski binding withthe spring plunger detached. In FIGS. 19 and 20 are shown intermediatepositions of the spring plunger and of one leg of the torsion springduring the stepping-out procedure.

The function of the ski binding in accordance with the earlier versionsis as follows: Upon stepping into the open binding, the ski boot notshown herein is pushed obliquely from above into the retaining shell 40.

Then, the ski boot together with the retaining shell 40 is swungdownwards through the position in FIG. 16 to the position in FIG. 14 andlocked in position by the locking pins 32, which enter the through-holesin the sole extension. The spring plunger 360, which can be pivotedabout the pin 50, slides with its detent 361 over the crossbar 43 of theretaining shell 40 (see FIG. 16) and is finally locked in the latchinggroove 43a of the crossbar 43 (cf. FIG. 14). This closes the binding,and the retaining shell 40 as well as the pivoting part 30 can bepivoted together about the transverse pin 20 against the action of anelastic element (cf. the element 90 in FIG. 1) not shown herein.

If, however, the skier desires to step out of the binding with the skiboot, he presses the tip of his ski pole into the depression 362 of thespring plunger 360, thereby swivelling the latter in counterclockwisedirection against the force of the interlock spring 80 shown in FIGS. 14and 17. At the same time, the detent 361 is lifted out of the latchinggroove 43a of the crossbar 43 of the retaining shell 40, so that thecrossbar can be swung so long relative to the pivoting part 30 that thelocking pins 32 leave the recesses in the sole extension of the skiboot, whereby the skier must press down with his ski pole the springplunger 360 in the open position during the entire stepping-outprocedure.

Now, in order to facilitate this stepping-out procedure, the springplunger 360 is locked by the leg 306b of the torsion spring 306 in thepivoted position in accordance with the modification of the invention(see FIGS. 15 and 18), with the result that the skier, during thestepping-out procedure, must not hold the spring plunger 360 in thepressed-down condition. Rather, he can support himself with his two skipoles on the cross-country track during the stepping-out procedure.

During this stepping-out procedure, the leg 306b of the torsion spring306 is pressed with a short unproductive movement through the crossbar43 of the retaining shell 40 via the latching projection 365 of thespring plunger 360, whereby its detent 361 has already reached the upperterminal area of the crossbar 43 of the retaining shell 40 (FIG. 19).The result is that the torsion spring 306, upon further upward swingingof the retaining shell 40 by means of the crossbar 43 and supported bythe interlock spring 80, is swung (pressed) back to its stand-byposition.

Thus, the torsion spring 306 is automatically returned to its initialposition if there is any random detachment. The unproductive movementmentioned above is dimensioned such that the upperside of the crossbar43 of the retaining shell 40 is overlapped by the detent 361 of thespring plunger 360 during the stepping-out procedure, so thatre-engagement or locking is ruled out (FIGS. 19 and 20). Thus, thebinding is prepared for a new stepping-in procedure.

The torsion spring depicted in FIG. 21, which corresponds to the torsionspring 306 of the preceding specific embodiment shown in FIGS. 13 to 20,is generally denoted 316. This torsion spring 316--viewed from theside--is shaped essentially like a U. It has two legs 316a, which areanchored in the pivoting part 360 of the binding. The two other legs316b are interconnected by a crossbar 316c. This crossbar 316c is passedin the correspondingly wide groove of the spring plunger 360. The turns316d of the torsion spring 316 disposed between the legs 316a and 316bare arranged on the transverse pin 30 of the ski binding mounted in thesupporting structure 10.

The invention is not limited to the specific embodiments discussedhereinabove. In the second embodiment, the construction of the crossbarof the retaining shell with an elevated area for additional locking ofthe spring plunger can also be effected in accordance with FIGS. 8 and9. In the second embodiment, the reinforcement of the closing force ofthe retaining shell can also be realized in like manner. Should theclosing force of the retaining shell be increased further, the positionof the spring plunger when the binding is open must be tilted morestrongly in its direction of closing than in the closed state, so thatthe spring deflection during the closing of the binding will be greater.This could, for example, be achieved by means of a fillet-shaped stopwhich is milled more deeply in the spring plunger. By giving the springplunger and the crossbar different designs, the position of the springplunger--with the binding open and closed--can be varied, so that thedistance of the angle of traverse of the spring plunger during theclosing of the binding can be varied.

Furthermore, the end of the corresponding leg of the torsion springpassed in the groove of the spring plunger can also be provided with arounded, e.g., spherical, head.

We claim:
 1. A ski binding for attachment to a ski and for retaining aski boot having a hook element extending therefrom, the ski bindingcomprising:a support structure for disposition on the upper surface of aski; a horizontal transverse pin attached to said support structure andextending transverse to the upper surface of the ski; a pivoting parthaving a first end, a second end, and a mid-portion disposed betweensaid first and second ends, said first end including a pivot pindisposed thereon, said second end having at least one locking pinextending therefrom, and said mid-portion being pivotably connected tosaid horizontal transverse pin; an elastic element disposed on saidsupport structure for contacting said pivoting part to resist pivotalmovement of said pivoting part about said transverse pin; a bootretaining shell pivotably mounted about said transverse pin for movementbetween an opened position and a closed position and having a recessdisposed therein, said locking pin for projecting through both saidrecess and the hook element of a ski boot when said retaining shell isin said closed position, and for releasing the hook element of the skiboot when said retaining shell is in said opened position; a springbiasingly disposed between said pivoting part and said retaining shellfor urging said retaining shell to said opened position; and a springplunger pivotably mounted about said pivot pin of said pivoting part forlocking said retaining shell in said closed position.
 2. A ski bindingfor attachment to a ski and for retaining a ski boot having a hookelement extending therefrom, the ski binding comprising:a supportstructure for disposition on the upper surface of a ski; a horizontaltransverse pin attached to said support structure and extendingtransverse to the upper surface of the ski; a pivoting part having afirst end, a mid-portion, and a second end, said first end including apivot pin disposed thereon, said mid-portion being pivotably connectedto said horizontal transverse pin, and said second end having at leastone locking pin extending therefrom and angled toward said horizontaltransverse pin, said locking pin including a circular arc segmentdisposed therein for engaging the hook element of the ski boot; anelastic element disposed on said support structure for contacting saidpivoting part to resist pivotal movement of said pivoting part aboutsaid transverse pin; a boot retaining shell pivotably mounted about saidtransverse pin for movement between an opened position and a closedposition and having a recess disposed therein, said locking pin forprojecting through both said recess and the hook element of the ski bootwhen said retaining shell is in said closed position, and for releasingthe hook element of the ski boot when said retaining shell is in saidopened position, said retaining shell further including a crossbarextending therefrom, said crossbar having a latch groove disposedtherein; a spring biasingly disposed between said pivoting part and saidretaining shell for urging said retaining shell to said opened position;and a spring plunger pivotably mounted about said pivot pin of saidpivoting part and having a portion for engaging said latching groove ofsaid crossbar to lock said retaining shell in said closed position.
 3. Aski binding as set forth in claim 2 wherein said boot retaining shellfurther includes opposing side walls having bearing surfaces angledtoward each other, and said locking pin of said pivoting part includes alinear segment extending from said circular arc segment to a distal endthereof.
 4. A ski binding for attachment to the upper surface of a skihaving a central axis, the ski binding comprising:a support structurefor disposition on the upper surface of a ski; a horizontal transversepin attached to said support structure and extending transverse to theupper surface of the ski; a ski boot having a hook element extendingtherefrom; a pivoting part having a first end, a mid-portion, and asecond end, said first end including a pivot pin disposed thereon, saidmid-portion being pivotably connected to said horizontal transverse pin,and said second end having at least one locking pin extending therefromand angled toward said horizontal transverse pin, said locking pinincluding a circular arc segment disposed therein for engaging the hookelement of the ski boot and a linear segment comprising said circulararc segment with a distal end of said locking pin; an elastic elementdisposed on said support structure for contacting said pivoting part toresist pivotal movement of said pivoting part about said transverse pin;a retaining shell for retaining a portion of said ski boot therein, saidretaining shell being pivotably mounted about said transverse pin formovement between an opened position and a closed position and having arecess disposed therein, said locking pin for projecting through bothsaid recess and the hook element of the ski boot when said retainingshell is in said closed position, and for releasing the hook element ofthe ski boot when said retaining shell is in said opened position, saidretaining shell further including opposing side walls having bearingsurfaces angled toward each other and further including a crossbarextending therefrom, said crossbar having a latch groove disposedtherein; a spring biasingly disposed between said pivoting part and saidretaining shell for urging said retaining shell to said opened position;and a spring plunger pivotably mounted about said pivot pin of saidpivoting part and having a portion for engaging said latching groove ofsaid crossbar to lock said retaining shell in said closed position.
 5. Aski binding according to claim 4 wherein said bearing surfaces are eachangled at approximately 45° with respect to the central axis of the ski.6. A ski binding according to claim 3 wherein the ski boot includes alateral front area having converging support surfaces and guidesurfaces, the hook element extending from the lateral front area of theboot and having a U-shape and a cylindrical cross-section for engagementwith the circular arc segment of the locking pin.
 7. A ski bindingaccording to claim 6 wherein the U-shaped hook element includes opposinglegs and a mid-portion extending between and connecting the opposinglegs, and wherein the lateral front area of the boot includes solematerial extending therefrom, said legs being embedded in said solematerial, and said sole material being bevelled at angles ofapproximately 45° proximate locations where said opposing legs of saidhook element are connected to the mid-portion of the hook element.
 8. Aski binding according to claim 6 wherein the boot retaining shellfurther includes a bottom surface for supporting the guide surfaces ofthe ski boot and wherein the support surfaces of the ski boot areparallel to the bearing surfaces of the retaining shell when the skiboot is disposed therein.
 9. A ski binding according to claim 8 whereinthe pivot part further includes a bottom surface portion that extends ina direction away from the surface of the ski, and the bottom surface ofthe retaining shell includes openings disposed therein, said openingsbeing located at positions between said transverse pin and the lateralfront surface of the boot when the boot is disposed in the bootretaining shell.
 10. A ski binding according to claim 4 wherein the hookelement moves along the linear segment of the locking pin and becomesseated in the circular arc segment in response to a downward forcetoward the ski exerted through a ski boot disposed in the retainingshell.
 11. A ski binding for attachment to a ski and for retaining a skiboot having a hook element extending therefrom, the ski bindingcomprising:a support structure for disposition on the upper surface of aski; a horizontal transverse pin attached to said support structure; apivoting part having a first end, a second end, and a mid-portiondisposed between said first and second ends, said first end including apivot pin disposed thereon, said second end having at least one lockingpin extending therefrom, and said mid-portion being pivotably connectedto said horizontal transverse pin; an elastic element disposed on saidsupport structure for contacting said pivoting part to resist pivotalmovement of said pivoting part about said transverse pin; a bootretaining shell pivotably mounted about said transverse pin for movementbetween an opened position and a closed position and having a recessdisposed therein, said locking pin for projecting through both saidrecess and the hook element of the ski boot when said retaining shell isin said closed position, and for releasing the hook element of the skiboot when said retaining shell is in said opened position, saidretaining shell further including a crossbar extending therefrom, saidcrossbar having a latch groove disposed therein and an elevated areadisposed adjacent said latch groove; a spring biasingly disposed betweensaid pivoting part and said retaining shell for urging said retainingshell to said opened position; and a spring plunger pivotably mountedabout said pivot pin of said pivoting part and having a locking end,said elevated area of said retaining shell and said latch groovecooperating to retain the locking end in said latch groove to therebylock the retaining shell in said closed position, said spring plungerbeing selectively pivotable to release said locking end from theretained position.
 12. A ski binding for attachment to a ski and forretaining a ski boot having a hook element extending therefrom, the skibinding comprising:a support structure for disposition on the uppersurface of a ski; a horizontal transverse pin attached to said supportstructure; a pivoting part having a first end, a second end, and amid-portion disposed between said first and second ends, said first endincluding a pivot pin disposed thereon, said second end having at leastone locking pin extending therefrom, and said mid-portion beingpivotably connected to said horizontal transverse pin; an elasticelement disposed on said support structure for contacting said pivotingpart to resist pivotal movement of said pivoting part about saidtransverse pin; a boot retaining shell pivotably mounted about saidtransverse pin for movement between an opened position and a closedposition and having a recess disposed therein, said locking pin forprojecting through both said recess and the hook element of the ski bootwhen said retaining shell is in said closed position, and for releasingthe hook element of the ski boot when said retaining shell is in saidopened position, said retaining shell further including a crossbarextending therefrom, said crossbar having a latch groove disposedtherein; a spring biasingly disposed between said pivoting part and saidretaining shell for urging said retaining shell to said opened position;and a spring plunger pivotably mounted about said pivot pin of saidpivoting part and having a portion for engaging said latching groove ofsaid crossbar to lock said retaining shell in said closed position, saidspring plunger being radially displaced by a first angle α when saidretaining shell is moved from said opened position to said closedposition, and said spring plunger being radially displaced by a secondangle β when said retaining shell is moved from said closed position tosaid opened position, said first angle being substantially equal to orgreater than said second angle.
 13. A ski binding according to claim 12wherein the plunger is disposed at substantially the same radialposition relative to said pivot pin when said retaining shell is in saidopened position and when said retaining shell is in said closedposition.
 14. A ski binding according to claim 12 wherein said crossbarof said retaining shell includes an elevated area disposed proximatesaid latch groove and said spring plunger includes a stop for engagingsaid elevated area when said retaining shell is in said opened position.